Fixes Vincit#1676

brianmcd · koskimas · commit e6466352e8ec · 2020-02-12T22:38:04.000+02:00
diff --git a/lib/utils/identifierMapping.js b/lib/utils/identifierMapping.js
@@ -21,7 +21,14 @@ function memoize(func) {
 // camelCase to snake_case converter that also works with non-ascii characters
 // This is needed especially so that aliases containing the `:` character,
 // objection uses internally, work.
-function snakeCase(str, { upperCase = false, underscoreBeforeDigits = false } = {}) {
+function snakeCase(
+  str,
+  {
+    upperCase = false,
+    underscoreBeforeDigits = false,
+    underscoreBetweenUppercaseLetters = false
+  } = {}
+) {
   if (str.length === 0) {
     return str;
   }
@@ -52,12 +59,16 @@ function snakeCase(str, { upperCase = false, underscoreBeforeDigits = false } =
     // Test if `char` is an upper-case character and that the character
     // actually has different upper and lower case versions.
     if (char === upperChar && upperChar !== lowerChar) {
-      // Multiple consecutive upper case characters shouldn't add underscores.
-      // For example "fooBAR" should be converted to "foo_bar".
-      if (prevChar === prevUpperChar && prevUpperChar !== prevLowerChar) {
-        out += lowerChar;
-      } else {
+      const prevCharacterIsUppercase =
+        prevChar === prevUpperChar && prevUpperChar !== prevLowerChar;
+
+      // If underscoreBetweenUppercaseLetters is true, we always place an underscore
+      // before consecutive uppercase letters (e.g. "fooBAR" becomes "foo_b_a_r").
+      // Otherwise, we don't (e.g. "fooBAR" becomes "foo_bar").
+      if (underscoreBetweenUppercaseLetters || !prevCharacterIsUppercase) {
         out += '_' + lowerChar;
+      } else {
+        out += lowerChar;
       }
     } else {
       out += char;
diff --git a/tests/unit/utils.js b/tests/unit/utils.js
@@ -141,6 +141,35 @@ describe('utils', () => {
       testUnderscoreBeforeNumbers('fooBar:spamBaz:troloLolo', 'foo_bar:spam_baz:trolo_lolo');
       testUnderscoreBeforeNumbers('fooBar.spamBaz.troloLolo', 'foo_bar.spam_baz.trolo_lolo');
 
+      testUnderscoreBetweenUppercaseLetters('*', '*');
+
+      testUnderscoreBetweenUppercaseLetters('foo', 'foo');
+      testUnderscoreBetweenUppercaseLetters('fooBar', 'foo_bar');
+      testUnderscoreBetweenUppercaseLetters('foo1Bar2', 'foo1_bar2');
+      testUnderscoreBetweenUppercaseLetters('fooBAR', 'foo_b_a_r');
+      testUnderscoreBetweenUppercaseLetters('fooBaR', 'foo_ba_r');
+
+      testUnderscoreBetweenUppercaseLetters('föö', 'föö');
+      testUnderscoreBetweenUppercaseLetters('fööBär', 'föö_bär');
+      testUnderscoreBetweenUppercaseLetters('föö1Bär2', 'föö1_bär2');
+      testUnderscoreBetweenUppercaseLetters('föö09Bär90', 'föö09_bär90');
+      testUnderscoreBetweenUppercaseLetters('fööBÄR', 'föö_b_ä_r');
+      testUnderscoreBetweenUppercaseLetters('fööBäR', 'föö_bä_r');
+
+      testUnderscoreBetweenUppercaseLetters('foo1bar2', 'foo1bar2');
+      testUnderscoreBetweenUppercaseLetters('Foo', 'foo', 'foo');
+      testUnderscoreBetweenUppercaseLetters('FooBar', 'foo_bar', 'fooBar');
+      testUnderscoreBetweenUppercaseLetters('märkäLänttiÄäliö', 'märkä_läntti_ääliö');
+
+      testUnderscoreBetweenUppercaseLetters(
+        'fooBar:spamBaz:troloLolo',
+        'foo_bar:spam_baz:trolo_lolo'
+      );
+      testUnderscoreBetweenUppercaseLetters(
+        'fooBar.spamBaz.troloLolo',
+        'foo_bar.spam_baz.trolo_lolo'
+      );
+
       function test(camel, snake, backToCamel) {
         backToCamel = backToCamel || camel;
 
@@ -162,6 +191,16 @@ describe('utils', () => {
           expect(camelCase(snakeCase(camel, opt), opt)).to.equal(backToCamel);
         });
       }
+
+      function testUnderscoreBetweenUppercaseLetters(camel, snake, backToCamel) {
+        backToCamel = backToCamel || camel;
+        const opt = { underscoreBetweenUppercaseLetters: true };
+
+        it(`${camel} --> ${snake} --> ${backToCamel}`, () => {
+          expect(snakeCase(camel, opt)).to.equal(snake);
+          expect(camelCase(snakeCase(camel, opt), opt)).to.equal(backToCamel);
+        });
+      }
     });
   });
 
diff --git a/typings/objection/index.d.ts b/typings/objection/index.d.ts
@@ -1285,6 +1285,7 @@ declare namespace Objection {
   export interface SnakeCaseMappersOptions {
     upperCase?: boolean;
     underscoreBeforeDigits?: boolean;
+    underscoreBetweenUppercaseLetters?: boolean;
   }
 
   export interface ColumnNameMappers {

Original file line number	Diff line number	Diff line change
`@@ -1285,6 +1285,7 @@ declare namespace Objection {`
`1285`	`1285`	`export interface SnakeCaseMappersOptions {`
`1286`	`1286`	`upperCase?: boolean;`
`1287`	`1287`	`underscoreBeforeDigits?: boolean;`
	`1288`	`+ underscoreBetweenUppercaseLetters?: boolean;`
`1288`	`1289`	`}`
`1289`	`1290`
`1290`	`1291`	`export interface ColumnNameMappers {`